Work tower



Dec. 23, 1969 R. E. SMITH, JR

WORK TOWER 16 Sheets-Sheet 1 Filed Nov. 20. 196'? Dec. 23, 1969 RYE.sum-l, JR 3,485,321

WORK TOWER Filed Nov. 20, 1967 16 Sheets-Sheet 2 jjj/a@ ZZ fl .5

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Dec. 23, 1969 Filed Nov. 26, 1957 R. E. SMITH, .m 3,485,321

- WORK TOWER 16 Sheets-Sheet 3 Dec. 23, 1969 R. E. SMITH, .1R 3,485,321

WORK TOWER Filed Nov. 20, 1967 16 Sheets-Sheet 4 ji@ 5 .25, Q f

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WORK TOWER Filed Nov. 20, 1967 16 Sheets-Sheet 5 11g 7 L .D7 I

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WORK TOWER Filed NOV. 20, 1967 16 Sheets-Sheet 6 El] Y IV [El {El} 242.g l ,y

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Dec. 23, 1969 WORK TOWER 16 Sheets-Sheet 7 Filed NOV. 20, 1967 Dec. 23,1969 R. E. 5mm, JR

WORK TOWER 16 Sheets-Sheet 8 Filed NOV. 20, 1967 16 Sheets-Sheet 9 WORKTOWER R. E. SMITH, JR

Dec. 23, 1969 Filed Nov. 20, 1967 Dec. 23, 1969 R. E. SMITH, 1R3,485,321

WORK TOWER Filed Nov. 20, 1967 16 Sheets-Sheet 1o Dec. 23, 1969 R. E.SMITH, JR

WORK TOWER 16 Sheets-Sheet 11 Filed Nov. 20, 1967 Dec. 23, 1969 R. E.SMITH, JR

WORK TOWER 16 Sheets-Sheet x2 Filed NOV. 20. 1967 INM,

Dec. 2s, 1969 R. E. SM'IT'H, JR 3,485,321

WORK TOWER Filed NOV. 20, 1967 16 Sheets-Sheet 125 Dec. 23, 1969 yR. E.SMITH, .1R

WORK TOWER 16 Sheets-Sheet 14 Filed Nov. 20, 1967 Dec. 23, 1969 R. E.Mlm JR 3,485,321

WORK TOWER Filed Nov. 2o, 1967 1e sheets-sheet 15 Dec. 23, 1969 R. E.SMITH, JR 3,485,321

WORK TOWER Filed Nov. 20, 1967 f 16 Sheets-Sheet 1e 3,485,321 WURK TOWERRaymond E. Smith, Ir., 385 E. Greenwood Ave., Lake Forest, Ill. 60045Filed Novu 20, 1967, Ser. No. 691,668 Int. Cl. Elllg N; E06c 5/04;F16g11/12 US. Cl. 182-131 14 Claims ABSTRACT 0F THE DISCLOSUREA A work towerwith a hydraulically positionable personnel platform and Work lplatformand hydraulically powered outriggers which are vertically andhorizontally positionable to tilt and support the work tower at avertical angle.

Introduction The present invention relates lto work towers and morespecifically to a fully portable work tower which provides exibleoperation with integral powered loading, unloading and erection in ahighly compact structure adapted for maneuverability in limited space.

The invention basically comprises a movable base supporting apersonnel-supporting platform, means for raising and lowering theplatform, and Outrigger means pivotally connected to the base. TheOutrigger means are extendable and are adapted to selectively verticallytilt the work tower for transportation.

Further objects, features and advantages of the invention pertain to theparticular arrangement and structure whereby the above mentioned aspectsof the invention are attained. The invention will be better understoodby reference to the following description and to the drawings forming apart thereof, which are substantially to scale, wherein:

FIGURE 1 is a top plan elevation of an exemplary work tower inaccordance with the present invention with outriggers extended;

FIGURE 2 is a sectional view taken along the line 2 2 of FIGURE 1;

FIGURE 3 is a front elevation taken along the line 3 3 of FIGURE l; v

FIGURE 4 is a side elevation taken along 4 4 of FIGURE l;

FIGURE 5 is an enlarged 5 5 of FIGURE 3;

FIGURE 6 is a sectional view taken along 6 6 of FIGURE 5;

FIGURE 7 is an enlarged view taken along the line 7 7 of FIGURE 3;

FIGURE 8 is a plan view showing the Work tower moving on end through anarrow doorway;

FIGURE 9 is a side elevation of the work tower in its collapsed positiontaken along theV line 9 9 of FIG- URE 3;

FIGURE l0 is a enlarged side elevation of the lower position of FIGURE 9with the work tower rotated 90 to a vertical position;

FIGURE 11 is a top plan view of the work tower in a vertical positionlooking in the direction of the line 11 11 of FIGURE l0;

FIGURE 12 is a bottom elevation of the lower portion of the work towertaken along the line 12-12 of FIGURE 1l;

FIGURE 13 is a front elevation of the work tower taken along the line 1313 of FIGURE 9;

FIGURE 14 is a plan elevation taken along the line 14-14 of FIGURE 9;

FIGURE 15 is a sectional view taken along the line 1-5-15 of FIGURE 14;

the line view taken along the line the line nited States Patent() "iceFIGURE 16 is a sectional view taken along 16-16 of FIGURE 9;

FIGURE 17 is a sectional view taken along 17 17 of FIGURE 9;

FIGURE 18 is a sectional view taken along 18-18 of FIGURE 9;

FIGURE 19 is a perspective view of the frame of an Outrigger ofthe worktower;

FIGURE 20 is an enlarged fragmentary view taken along the line 20 20 ofFIGURE 13;

FIGURE 21 is a sectional view taken along the line 21 21 of FIGURE 20;

FIGURE 22 is a fragmentary sectional view taken along the line 22 22 ofFIGURE 2l;

FIGURE 23 is a view similar to FIGURE 20 but with the Outrigger rotated45 FIGURES 24 through 29 are schematic side elevations successivelyillustrating the loading of the work tower of FIGURES l through 23 ontoa transport vehicle;

And FIGURES 30 through 32 are side elevations of the work tower ofFIGURES 1 through 29 in a vertical position.

the line the line the line Description of the exemplary embodimentReferring to the FIGURES 1 through 32, there is shown an exemplary worktower 20 in accordance with the present invention. The work tower 20 isa self-contained portable unit including a wheeled base 22 and apersonnel-supporting platform 24 raised and lowered from the base 22 bya rst hydraulically powered scissors linkage 26. The personnel platform24 mounts a separate work supporting platform 28 independently raisedand lowered by a second hydraulically powered scissors linkage 30.Pivotally connected to the base 22 at opposite sides are outriggers 32and 34 adapted to extend from the base. The outriggers 32 and 34 arevertically pivotable by integral hydraulic cylinders with respect to thebase 22 to selectively vertically tilt the entire work tower 20 to anydesired angle including a fully vertical position.

The entire work tower 20 is preferably actuated by hydraulic cylinderspowered by a hydraulic system on the base 22. Commercially availablehydraulic system components may be employed. Line current orself-contained batteries may be employed to drive the hydraulic pump.

Considering the base 22, it provides the basic connection point andsupport for the work tower 20. Preferably, it has two large iixed axiswheels 36 at a first end 3S and two large pivotable (castered) wheels atthe opposite or second end 40.

Each of the two outriggers 32 or 34 is adapted to act as an arm forhydraulically manuevering the entire work tower 20. The entire Outriggerunit is pivotally connected by its frame 41, shown in FIGURE 19, to thebase 22 by a vertical pin 42. The Outrigger is normally restrained fromhorizontal rotation by a securing pin 44 connecting an ear of theOutrigger frame 41 with the base 22. As shown in FIGURE 23, twodifferent apertures for the pin 44 may be provided. Thus, the Outriggermay be held parallel the side of the base 22 or horizontally pivoted toa 45 angle to the base 22 to provide lateral stability forrthe worktower as shown in FIGURE l. In either position, with the pin 44 in placethe Outrigger is secured to the base 22.

The outriggers each include an elongate Outrigger arm 46 pivotallysecured thereto for horizontal rotation about a pin 4S in the frame 41adjacent the inner end of the Outrigger arm 46. The arm 46 is arectangular tubular member and is adapted to slidably receive therein anextension arm 50. The extension arm 50 slides into either the inner orouter ends of the Outrigger arm 46, co-

3 linearly extending the Outrigger beyond the end of the work tower inthe first case and past the midpoint or center of gravity of the worktower in the other case. The extension arm 50 can also telescope almostentirely inside the Outrigger arm 46 for minimum extension as shown inFIGURES 30 through 32.

The Outrigger contains its own wheel system comprising a small casterwheel at the outer end of the Outrigger arm 46 and a small caster wheel51 at the outer end of the extension arm. The extension arm 50 also hasa pin lockable fixed axis wheel 52 Opposite its caster wheel 51. Byinserting the extension arm 50 in the Outrigger arm upside down, thewheel 52 is presented toward the oor rather than the caster wheel 51. Itwill be noted that, with the Outrigger arm in a horizontal position andthe work tower in its normal position, as in FIGURE 24, only the wheelson the base 22 contact the floor. The wheels on the base 22 extend belowthe wheels on the Outrigger arms and the extension arm, therebyproviding clearance for positioning the outriggers.

The Outrigger may be tilted vertically, i.e. about a horizontal axis, orthe base may be tilted vertically depending upon the position of theextension arm 50. This vertical movement may be either above or belowthe horizontal and is accomplished by the piston movement of a hydrauliccylinder 54. The selectable operation of the cylinder 54 provides ineffect a variable length arm connecting the outer end of the Outriggerarm 46 with a pivot point 56 on the Outrigger frame 41 spaced above thepiston 48. Thus expansion or contraction of the cylinder 54 respectivelylowers or raises the outer end of the Outrigger arm 46, thereby pivotingboth the Outrigger arm and the extension arm vertically about the pin48.

When the work tower is tilted into its vertical or on end position bythe outriggers 32 and 34, as in FIGURES 8 and 10 through 12, the worktower is supported and movable on the Outrigger wheels alone. The wheelson the base 22 are pivoted off the floor. Accordingly, referring toFIGURES through 32, to allow the retraction of the extension arm 50, anelongated lever 58 is provided to lift both the first end 38 of the baseand the outriggers slightly above the floor. The lever 58 has itsfulcrum point on the base 22 closely spaced above the floor to provide ahigh leverage ratio. The short arm of the lever below the fulcrum isadapted to engage the floor and to tilt up and hold the work tower andthe outriggers when the lever 58 is rotated from a generally vertical toa generally horizontal position.

The personnel-supporting platform 24 may be automatically from a compactfolded position to any selected working height with the personnelremaining on the work tower. Referring particulary to FIGURES 4 and 7,an effective yet simple hydraulically powered scissors linkage 26 raisesand lowers the platform 24 from the base 22 while maintaining thehorizontal level of the platform. The scissors linkage 26 includes atboth sides of the work tower 20 two elongate legs 60 and 62 centrallypivotally connected. The lower end of the leg 60 is pin connected to thefirst end 38 of the base 22. The corresponding overlying end of theplatform 24 is pin connected to the upper end of the leg 62. The upperend of the leg 60 has a roller which engages and rolls horizontallyalong the underside of the platform 24. Correspondingly, a roller on thelower end of the leg 62 rollably engages the base 22.

The lifting of the platform 24 is provided here by a hydraulic cylinder64. Because of the large forces and varying positions involved, aspecial lever link 66 connection is preferably provided between thehydraulic cylinder 64 and the scissors linkage 26. The cylinder 64 ispivotally secured at one end to the lower end of the leg 60. The pistonend of the cylinder 64 is pivotally secured to the Outer end of the link66. The link 66 is an elongate integral member and is pivotally securedto the lower portion of the leg 62 at a pivot point 68. Due

to the pivotal connections, the cylinder 64 and the link 66 are normallypulled colinearly by the cylinder 64. and the lifting force exerted bylthe cylinder 64 normally acts through the pivot point 68.

However, for the initial lifting movement of the work platform, i.e.when the scissors 26 are closed, a desired different lifting leverage isprovided. This is provided by a fulcrum projection 70 on the link 66.The projection 70 extends at right angles to the link 66 substantiallyspaced from the pivot point 68. When the scissors 26 are substantiallyclosed, as in FIGURES 9 and 15, the projection 70 operatively engages apoint of contact 72 on the leg 62 spaced substantially above the pivotpoint 68. It may be seen that in this position, the link 66 is notcolinear the cylinder 64. ILower pressure is needed in the cylinder 64for the initial lifting of the platform 24 than would be requiredwithout this arrangement.

The work supporting platform 28 may be independently raised and loweredabove the personnel-supporting platform 24 to place the work materialsat any desired height convenient to the workmen and the ceiling or workheight, thus greatly improving working efficiency in many applications.The work platform 28 is positioned and supported by a separate hydraulicpowered scissors linkage 30 connected to and overlying the personnelplatform 24 as shown in FIGURES 4 through 6. It differs somewhat fromthe personnel platform 24 system in that its hydraulic cylinder 73operates against a lever arm 74 which is rigidly secured to a leg of thescissors.

The personnel-supporting platform 24 preferably includes a centralframework 75 and foldable and removeble walkways 76 and 77 along eachside as shown in FIGURES l, 3, 13 and 18 for example. Each walkway ispreferably an integral unit providing horizontal flooring and verticaloutside safety railing. Each walkway is retained by a plurality of hooks78 which fit over horizontal pins 80. The pins 80 are inside the openends of tubular members 82 of the framework 75, thus providing lateralrestraint for the hooks 78. Rotation of the walkways about the pins 80below the horizontal is prevented by the abutment of the inside edge ofthe walkway with the underside of the platform framework 75 at contactareas 84.

Each walkway 76 and 77 may be removed by lifting the hooks 78 off thepins 80. Further, the walkways can be pivoted upwardly to compactly foldover each other and the work tower when both of the tower platforms arein their lowered positions.

The walkways 76 and 77 may be constructed primarily of wood if desired.However, they may also be of metal construction. The entire work tower20 is preferably constructed with high strength yet relatively lightweight materials for portability. Suitable tubular metal construction isshown in the drawings.

The work tower 20 provides both flexible operation and compactportability without requiring either manual exertion or auxiliaryequipment. Both the operation and transportation can be accomplished bya single person operating the appropriate hydraulic valves, Outriggercomponents and the lever 58 without requiring a dock, crane or otherequipment even though the work tower may be of a weight which wouldnormally preclude manual movement. The work tower 20 is particularlysuitable for the needs of building contractors who must makeinstallations above the oor level. It may be constructed small eenoughto be transported to any job site in a pickup truck. At the job site, itcan be unloaded without assistance by manipulation of its own hydraulicoutriggers. The work tower can then Ibe easily moved and positioned onitS integral wheels. When in position, it may -be stabilized by its ownoutriggers. The work tower can also turn itself completely on end sothat it may move through narrow door openings. Both the equipment to beinstalled and the workers can be vertically positioned where desired bythe raising of the tower platforms to the respective desired workingheights. The personnel can work on both sides of the load on thewalkways Or one walkway may be removed for clearance if desired.

For stabilizing the work tower 20, the outriggers may be arranged andpositioned as shown :in FIGURES 1 and 2. The Outriggers are pivotedhorizontally as previously described, and the extension arm 50 ispositioned in the Outrigger arm 46 so that the pin lockable wheel 52 canbe locked and forcibly brought to bear against the fioor by theOperation of the hydraulic cylinder 54.

FGURES 24 through 29 illustrates the steps of selfloading the work tower20 Onto a vehicle. During unloading, the same steps are reversed.

In FIGURE 24, it may be seen that the Outrigger arms 46 and theextension arms 50 extend parallel the sides of the work tower. Theextension arms 50 extend from the inner end of the Outrigger arms 46with the caster wheel 51 down. Then, as shown in FIGURE 25, thehydraulic cylinder 54 is actuated and the second end 40 of the worktower is lifted above the vehicle floor level. At this point, the worktower is supported and movable on the wheels 36 at the first end 38 ofthe work tower and the caster wheels 51 on the extension arm. Thus, thework tower may be pushed forward until the second end 40 is over thevehicle iioor. Then the hydraulic cylinder 54 may be actuated to lowerthe wheels on the second end 40. Continued operation Of the hydrauliccylinder 54 can then lift the extension arm 5f) sufficiently for it tobe removed, turned over and inserted in the outer end of the Outriggerarm 46 as shown in FIGURE 26. Further operation of the cylinder 54 thenresults in lifting the front end 38 above the vehicle fioor level sothat it may be rolled into the truck on the wheels 52 and the wheels onthe second end 40 as shown in FIGURES 27 and 28. The cylinder 54 maythen be actuated again to lift the outriggers into a vertical positionas shown in FIGURE 29.

It may be seen that there has been described herein a work tower whichis extremely versatile and transportable. The apparatus described hereinis presently considered to be preferred; however, it is contemplatedthat further variations and modifications within the purview of thoseskilled in the art can be made herein. The following claims are intendedto cover all such variations and modifications as fall within the truespirit and scope of the invention.

What is claimed is:

l. A movable work tower adapted for compact storage and movement througha narrow opening comprising:

a horizontally disposed base having predetermined lateral dimensions andadapted to support said work tower on a generally horizontal firstsurface;

a personnel-supporting platform connected tO said base;

means for raising and lowering said personnel-supporting platform abovethe first surface, said personnel supporting platform in its loweredposition and said base being of a combined thickness less than either ofsaid predetermined lateral dimensions;

and Outrigger means pivotally connected to said base at a point to oneside of the center thereof;

said Outrigger means being extendable from said base and having rollermeans for engaging the first surface;

said Outrigger means being adapted to tilt said base on end so said baseis oriented vertically relative to said generally horizontal firstSurface with said roller means serving to rollably support said worktower for movement through said confined opening and said Outriggermeans being further adapted to provide lateral stabilizers for said worktower when said base is in its horizontal postion.

2. The work tower of claim 1 further including a work support platformOn said personnel-supporting platform and means for independentlyraising and lowering said work support platform relative said firstsurface and said personnel-supporting platform.

3. A movable work tower comprlsing:

a base having first and second ends and wheels movably supporting saidbase on a 'horizontal first surface,

a personnel-supporting platform connected tO said Jbase,

means for raising and lowering said personnel-supporting platform abovesaid first surface,

an elongate Outrigger arm having inner and outer ends,

each said Outrigger arm being pivotally connected for vertical andhorizontal rotation about its inner end at opposite sides of said firstend of said base,

anextension arm colinearly projecting from each said Outrigger arm,

said extension arm having lockable means for rollably engaging saidfirst surface at its Outer end,

both said inner and outer ends of said Outrigger arm being adapted toselectively connect with said extension arm,

wheel means on said outer end of said Outrigger arm adapted to engagesaid first surface,

hydraulic means connecting between said Outrigger arm and said base forvertically pivoting said base relative to said Outrigger about saidfirst end of said base,

and lever means, pivotally connected to said base adjacent saidoutrigger means, for lifting said base and said Outrigger means fromsaid first surface for movement of said extension arm.

4. The work tower of claim 3 further including a work support platformon said personnel-supporting platform and means for independentlyraising and lowering said work support platform relative said firstsurface and said personnel-supporting platform.

5. A movable work tower comprising:

a base having first and second ends and adapted to support said worktower on a generally horizontal first surface,

a personnel-supporting platform connected to said base,

means for raising and lowering said personnel-supporting platform abovethe first surface,

and Outrigger means pivotally connected to said base,

said Outrigger means being extendable from said base and having meansfor engaging the first surface,

said Outrigger means being adapted to selectively vertically tilt saidfirst and second ends of said base above the first surface and toprovide lateral stabilizers for said work tower,

and lever means, pivotally connected to said base adjacent saidOutrigger means, for lifting said base and said Outrigger means fromsaid first surface for extension and retraction of said Outrigger means,

6. The work tower of claim 5 further including a Work support platformon said personnel-supporting platform and means for independentlyraising and lowering said work support platform relative said firstsurface and said personnel-supporting platform.

7. The work tower of claim 5 wherein said means for raising and loweringsaid personnel-supporting platform includes,

a scissors connector therebetween with at least two pivotally connectedlegs and lifting means moving said scissors connector between Openingand closing positions,

said lifting means including a hydraulic cylinder and a lever linkagepivotally connecting with said hydraulic cylinder and pivotallyconnecting with a first point on said scissors connector,

said lever linkage providing a lifting connection of said hydrauliccylinder with a second point on said scissors connector substantiallyspaced from said first point in said closing position of said scissorsconnector,

and said lever linkage providing a lifting connection of said hydrauliccylinder with said scissors connector only at said first point duringthe remainder of the movement of said scissors connector. 8. The movablework tower of claim '7 wherein said lever linkage is an elongateintegral member having a fulcrum portion projecting at right anglesthereto, said fulcrum portion engaging said second point of connectiononly in said closing position of said scissors connector.

9. In a portable work tower having an ambulatory base and a liftplatform supported thereon, self-loading means adapted for lifting saidwork tower between generally horizontal rst and second surfaces atvertically spaced levels comprising:

rst lever means supported on the underside of said base adjacent one endthereof and adapted for pivotal movement about a generally horizontalaxis;

second lever means comprising an elongated lever arm adapted forselective locking engagement with said first lever means in each of afirst and a second position in which said second lever arm extends alonga line generally parallel to the longitudinal axis of said Work tower inrespective opposite directions from said first lever means;

and power operated actuator means coupled between said first lever meansand said base for pivoting said rst lever means to displace, throughcoaction of said elongated lever arm and one of said first and secondsurfaces, one end of said work tower between said lirst and secondsurfaces when said elongated lever arm is in said rst position and fordisplacing the other end of said work tower between said rst and secondsurfaces when said elongated lever arm is in said second position.

10. The self-loading means of claim 9 in which said first lever meansand said elongated lever arm of said second lever means are eachcomprised of a hollow channel member with said hollow channel of saidfirst lever means being of internal dimensions for snugly receiving oneend portion of said elongated lever arm therewithin and in which saidfirst lever means and said elongated lever arm are selectivelymaintained in locking engagement by a bolt extending through alignedapertures in said hollow channel members.

11. The self-loading means of claim 10 in which said power operatedactuator means comprises a hydraulically operated piston and cylinderarrangement with said piston and said cylinder being each pivotallymounted to a respective one of said rst lever means and said base.

12. The self-loading means of claim 11 and including wheel means at eachend of said elongated lever arm of said second lever means for rollablyengaging said lirst and second surfaces. Y

13. A portable work tower for raising objects to a predeterminedsubstantial height and for folding into a compactly stored unitcomprising:

base means including a generally rectangular bed having wheels thereonsupporting said base for rollable movement;

first platform means having a support deck and further having poweractuated lifting apparatus for displacing said support deck between alowered position substantially contiguous said bed of said base meansand a raised position a predetermined distance above said bed;

second platform means, mounted on said support deck of said firstplatform means, having an associated support deck and further havingpower actuated lifting apparatus for displacing said associated supportdeck between a closed position substantially contiguous said supportdeck of said first platform means and a raised position a'predetermineddistance above said support deck of said lirst platform means;

and a pair of personnel carrying platform means hingedly mounted toopposed sides of said support deck of said second platform means andpivotable inwardly from normal work positions lateral of said secondplatform means toward one another to lie in overlapping relation on saidlowered support deck of said second platform means to effect a compactstorage of said personnel carrying platform means.

14. The work tower of claim 13 in which said pair of personnel carryingplatform means each comprise a personnel supporting deck and a guardrail mounted about the outer periphery about said deck.

References Cited UNITED STATES PATENTS 1,577,989 3/ 1926 Sieber 182--692,656,942 10/ 1953 Helms 214-515 2,843,430 7/ 1958 Johnson 182-632,935,218 5/1960 Fritz 182-63 3,015,497 l/1962 Aldred 182-17 3,259,3697/1966 Gridley 182-141 3,283,831 1l/1966 Bronder 214-515 3,411,64611/1968 Emery et al 254-45 REINALD P. MACHADO, Primary Examiner U.S. Cl.X.R.

